1. Field of the Invention
This invention relates to molded circuit boards.
2. Related Art
Circuit boards conventionally are made from fiber reinforced synthetic resin and from ceramic, the ceramic boards, or substrates, normally being for relatively small boards and often experiencing high temperatures in use. Fiber reinforced synthetic resin boards can vary considerably in size.
Various disadvantages relate to conventional materials. Ceramic is not available in large sizes, drilling for through hole connection is not economical, and there is a possibility of breakage. The cost of a ceramic board or substrate increases rapidly with increase in size and in thickness, particularly over 4".times.4" or over 0.04" in thickness, or both. Fiber reinforced synthetic resin can be obtained in large sizes, but is only readily available in planar rectangular form. Circuit boards of such material are readily drilled, but thermal mismatch can occur between the board and ceramic packaged components, or ceramic substrates, mounted on the board. A normal circuit board having a circuit pattern thereon requires numerous process steps to produce.
Conventional circuit boards have planar surfaces, with circuit patterns formed on one or both surfaces. Mounting of some components can be difficult as they are not of stable form, for example cylindrical, or having only two contact positions which do not support the component in a stable position.